Flip-flops are bought from a product shot and judged in about a week. These four decisions are what decide the second part.

The toe post is the whole product

A flip-flop fails when the toe post pulls out of the footbed, and that happens when the post was glued into a blind hole rather than pulled through the sole and heat-flared underneath.

You can check this in two seconds: turn a sample over and look at the underside of the sole. A flared anchor is visible. A smooth sole with no anchor means the post is held in by adhesive alone.

Density, not thickness

EVA foam takes a compression set: under repeated load it flattens and does not recover. A thick low-density footbed compresses fastest and ends up thinner than a dense one that started thinner.

So ask for the density and treat sole thickness as a styling choice. Thickness is the number that photographs well; density is the number the wearer experiences in month three.

Sublimate the strap, and lay it out per size

The strap bends at the toe post with every step. A surface print crazes exactly there. Sublimation puts the colour into the material, so there is nothing on the surface to crack.

And strap length changes with size, so one artwork laid out for a large pair runs off the ends of a small one. Insist on seeing the smallest and largest sizes proofed.

Match the format to the surface

For a spa, a pool or a locker room, a slide with no toe post is usually the better answer: nothing to fail, faster to put on, easier to launder.

For any wet hard floor, ask about the tread pattern. A flat sole floats on the water film; a patterned tread gives the water somewhere to go.

What to send when you ask for a quote

Artwork, quantity, size spread, whether people will walk in them, and where they will be worn. That is enough for a real quote and a mockup the same day.

Fine detail closes up in foam and on a narrow strap, so most marks need opening out. We redraw free.